Process of freeing waste waters containing cyanids and sulfocyanids from poison.



No. 897,735. PATEN'TED SEPT. 1, 1908.

P. GOLDBERG.

PROCESS OF PREEING WASTE WATERS CONTAINING GYANIDS AND SULFOGYANIDS FROM POISON.

APPLICATION FILED JAN.23,1906.

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Ares PATENT our-res.

PAUL GOLDBERG, OF FLGRSHEIM-ON-THE-WIAIN, GERMANY, ASSIGNOR TO THE FIRM OF CHEMISGHE FABRIK FLQRSHEIM DR. GERMANY.

H. NOERDLINGER, OF FLtjRSHEIhLON-THE-MAIN;

PROCESS OF FREEING- WASTE WATERQ CGNTAINING GYANIDS AND SULFOCYANIDS FROM 1POISON.

No. seams.

To all whom it may concern:

Be it known that I, PAUL Gornss'ne, chemist, a subject of the Kingof Prussia, residing at Florsheini-on-the-Main, Germany, have invented certain new and useful Improvements in Processes of Freeing Waste Waters Containing Cyanide and Sulfocy-' anids from Poison, of which the following is a s ecification. I '4 This invention has reference to a process for freeing waste liquors, solutions and other liquids containing cyanoand sulfo-cyanocompounds" from poison, rovision being made at the same time for o taining hydrocyanic acid or cyanids, The process is particularly intended for the purpose of destroy In carrying the process into efiect, the liq-- Specification 02 Letters Patent.

Application filed January 23, 1906. Serial No. 297,509.

'uids are treated according to my invention in acid solution with air, by which means the cyano-compounds are converted into hydro-cyamc acid, which latter may then be driven off and condensed.

In case of sulfo-cyanid-compounds being also present besides cyanids, an' addition of corresponding amounts of oxidizing substances is made to the liquids, whereafter in this case also hydro-cyanic acid may be driven off and collected, the hydrocyanic acid being either condensed as such or being absorbed in solvents orjcombined' by chemicals.

The accompanying drawing illustrates a vertical section of an apparatussuch as may be employed in'the process.

A is a still into which is inse ted a pipe (1 ending in a perforated coil'b; the pipe a is connected by the cylinder E with pipesc and d, having valves 1 and? and leading from a blowing apparatus. Another valve 3 is arranged between the cylinder E and. the pipe a. A part of the pipe 0 is formed. into a helix, which passes through a steam chamber D. The still A is fitted with a steam Patented'sept. 1, 190a.

neck of the still A, a pipe 6 leads into a receiver F, from thence a p'pe 9 may or may not lead into'more receivers.

In carrying out the process, the liquids to be purified are filled into the still A. This may be heated by means of the steam jacket B. The valve 3 is then opened and'air blown through the liquid by the coil b and pipe a. This airmay be previously heated; .in this case.the valve 1 is opened, valve 2 being closed, so that the air passes through the heated spiral pipe 0, or cold air may be used jacket B, an outlet f, and cock I. From the by closing the valve .1, opening 2, and letting the air pass through Ofcourse, hot and cold air may be mixed by opening both the valves land 2. A certain pressure of air is maintained by means of the'cylinder E and the valves 1, 2 and 3'. The distillation-prod not is passed'by e into'the receiver F, which is charged with an absorbent. or neutralizing;

agent,.and from. which a pipeflg leads either to the chimney or to a second or other w ceivers, if this should prove necessary.

The operation of the process may be ex- I plained by the following example:'0. 5

residue neither hydro-cyanlc acid nor sulfocyanhydric acid could be detected. In the same manner the destruction of the poison is also efiected in the waste liquors left after] the driving-0d of the ammonia from the waste liquors of'gas works treated with lime.-

2' liters of this waste liquor from gas Works showing a contents of about one part of sulfo-cyanld in one thousand'parts, were acidified by sulfuric acid, and t en treated with pyrolusite, and a c'urrentofair was then r blown through the liquor at 50 degrees centigrade. The distillation roduct was al.- lowed to pass into 200 cubic centimeters of standard caustic soda solution. linesolution shows a very decided reaction of Prussian blue. In the residue from the distillation neither sulfo-cyanhydric acid nor' hydro-cyanic acid could be detected.

The alka.

- liquors and to blow air through them. waste liquors which are freed from their po1sonous ingredients 1n this manner, may

'- By keeping the temperature down when blowing the liquor .with air, the operator is at' liberty to decrease the contents of water in' the distillate or to regulate thejsame. The ,air may be heated or gases of combus- 'tio1 1, for' instance waste gases, may be used which possess 'a still higher temperature, .Then, the liquors themselves may likewise be heated.

oeivers containing any suitable means ca pable'of absorbing or ofjretaining hydro, cyame acid.

Of such means the following may 'be mentioned:solution of caustic alkali for the production of cyanid-,'solution of iron for the production offerro-cyanidcompounds 'or the like; i In the case of waste liquors containing only cyanids, the oxidizing additions referred to, which are necessary in the case of sulfo-cyanid-compou1ids, are not required. It is suliicient to acidify these The be allowed to run to waste, after having been previously neutralized, if required, by the addition of lime'or of other agents for neutrahzmg acids.

The'new process is suitable for the destruc tion of the poisonous constituents of waste liquors of co'king plants, gas works, manu factories of ammonia and the like, as we'll as for the production of hydro-cyanic acid and cyanids, offerro-cyanic-compounds and the like, from the waste liquors referred to.

From the processes heretofore known, the process 'hereinbe'fore described 'is distinguished by the fact ofoperating in acid so- 'lut-ion inthe first place and by blowing out the poisonous gases and liquors by an and then collecting the same instead of driving them off by distillation by heating directly.

By this treatnient with air anoxidation of the waste liquors is produced which isstill increased in the presence of sulfur by the ad- (ht on of oxidizing agents.

It was not to be expected that comparatively small quantities of hydro-cyanic acid would resist to the action ofinineral acids and of oxidizing agents on the other'hand at such a high degree ofdilution and that they could be cartied off unchanged. by blowing without being 1 oxidized into formic acid, cyanic acid or carbonic acid, while the sulfur contents are acprocess.

gree of dilution, consisting in acidifying the from ammonia-manufactories, coking plants,

gas and tar, manufactories and the like con taining cya-mds, sultocyamds, formic acids,

I g phenols and hydrocarbons in a very high de- Fhe esca 111 air is inane to ass into rel gree of dilution, consisting in acidifying the waste waters, 1n heating the same, and in blowing a'current of air through the same,

whereby the deleterious compounds are driven off.

3. The process .or purirymg waste waters from ammonia-manufactories, coking plants, gas and tar manufactories and the like, containing 'cyanids, sulfocyanids, formic acids,

phenols and hydrocarbons in a. Very high de gree of dilution, consisting in acidifying the waste waters and in blowing a currentof ho air through the same, whereby, the poisonous compounds are drivenotf.

l. The process of purifyingwaste waters from ammonia-mannfactories, coking-plants,

gas and tar manufactories and the like 0011-.

taini'ng cyanids, sulfocyanids, formic acids, phenols and hydrocarbons ina Very high de gree of dilution, consisting in acidifying the waste waters. and in l-ilowing-a current of hot gases through the same, whereby the poison-' ouscompoi'inds are driven off.

The process of purifying waste waters fromammonia-manufactories, coking plants, gas and tar manufactoriesand the like, containing cyanids, sulfo'cyauids', formic acids, phenols and hydrocarbonsin a Yeryhigh degree of, dilution, consisting iii-acidifying the waste waters, in adding oxidizing means to the acidified waters,and'in blowing a current of air through the sameyw-hereby the poisonous compounds are driven off.

6. The process ofpurifyingwaste waters from ammonia-manufactories, coking plants,

gas and tar manufactories and the like containing cyanids, sulfocyanids, formic acids,

phenols and hydrocarbons in a Very high degree of dilution, consisting in acidifying the waste waters, in adding oxithmug means to the acidified waters, in heating the waters.

thus treated to about fifty degrees centi grade, and in blowing a current of air through the same, whereby the deleterious compounds are driveirofl.

In testimony whereof I have hereunto set myhand in presence of two subscribing witnesses. I

- PAULxGOLDBERG.

Witnesses OTTMAR Lon'w'n,

JEAN GRUND. 

